Question

我有两个数据库表，两个行都很多。第一个表格包含产品概述，第二个表格包含产品的附加信息。表格如下：


    #Products
    + ---------- + ------ + ------------ +
    | Product_Id | Status | EAN          |
    + ---------- + ------ + ------------ +
    | 1          | 1      | 0123456789   |
    | 2          | 1      | 9876543210   |
    | 3          | 1      | 6548214656   |
    | 4          | 2      | 245511411241 |
    | 5          | 1      | 8888888888   |
    | etc.       | etc .  | etc.         |
    + ---------- + ------ + ------------ +



     #Info
        + ------- + ------------ + --------- + ---------- +
        | Info_Id | EAN          | Info_Type | Info_Value |
        + ------- + ------------ + --------- + ---------- +
        | 1       | 0123456789   | brand     | brand1     |
        | 2       | 0123456789   | type      | type1      |
        | 3       | 0123456789   | price     | 0.00       |
        | 4       | 9876543210   | brand     | brand6     |
        | 5       | 9876543210   | type      | type3      |
        | 6       | 9876543210   | price     | 15.00      |
        | 7       | 6548214656   | brand     | brand34    |
        | 8       | 6548214656   | type      | type1      |
        | 9       | 6548214656   | price     | 99.00      |
        | 10      | 245511411241 | brand     | brand324   |
        | 11      | 245511411241 | type      | type1      |
        | 12      | 245511411241 | price     | 98.00      |
        | 13      | 8888888888   | brand     | brand1     |
        | 14      | 8888888888   | price     | 9.00       |
        | 14      | 8888888888   | type      | type4      |
        | etc.    | etc.         | etc.      | etc.       |
        + ------- + ------------ + --------- + ---------- +

通过以下查询，我可以通过匹配EAN来找到与产品相对应的附加信息：



     select    i.EAN
            , p.ProductStatus
            , max(case info_type when 'brand' then info_value end) as brand
            , max(case info_type when 'type' then info_value end) as [type]
            , max(case info_type when 'price' then info_value end) as price
        from #Info i
        inner join #Products p on p.ean = i.ean
        WHERE p.Status=1
        group by i.EAN, p.ProductStatus ORDER BY P.Product_id DESC LIMIT 10

这为我提供了下表：



     + ------------ + ------ + -------- + ----- + ----- +
        | EAN          | Status | brand    | type  | price |     
        + ------------ + ------ + -------- + ----- + ----- +
        | 0123456789   | 1      | brand1   | type1 | 0.00  |
        | 6548214656   | 1      | brand34  | type1 | 99.00 |
        | 9876543210   | 1      | brand6   | type3 | 15.00 |
        | 8888888888   | 1      | brand1   | type4 | 9.00  |
        | etc. (10 products)                               |
        + ------------ + ------ + -------- + ----- + ----- +

但是，现在我希望能够针对特定品牌，类型或价格进行过滤。例如，我只想选择价格大于50的产品（Info_Type = price AND Info_Value＆gt; 50.00），其次品牌是特定品牌，比如说“brand1”（Info_Type = brand AND Info_Value = brand1）。有人能告诉我如何将其包含在我的查询中吗？尝试了很多东西，最接近我得到的结果是以下查询：


    select    i.EAN
        , p.ProductStatus
        , max(case when (info_type = 'brand' AND info_value='brand1') then info_value end) as brand
        , max(case info_type when 'type' then info_value end) as [type]
        , max(case info_type when 'price' then info_value end) as price
    from #Info i
    inner join #Products p on p.ean = i.ean
    WHERE p.Status=1
    group by i.EAN, p.ProductStatus ORDER BY P.Product_id DESC LIMIT 10

但是，这会产生以下结果：

    + ------------ + ------ + -------- + ----- + ----- +
    | EAN          | Status | brand    | type  | price |     
    + ------------ + ------ + -------- + ----- + ----- +
    | 0123456789   | 1      | brand1   | type1 | 0.00  |
    | 6548214656   | 1      | NULL     | type1 | 99.00 |
    | 9876543210   | 1      | NULL     | type3 | 15.00 |
    | 8888888888   | 1      | brand1   | type4 | 9.00  |
    | etc. (10 products)                               |
    + ------------ + ------ + -------- + ----- + ----- +

我希望看到以下结果：

    + ------------ + ------ + -------- + ----- + ----- +
    | EAN          | Status | brand    | type  | price |     
    + ------------ + ------ + -------- + ----- + ----- +
    | 0123456789   | 1      | brand1   | type1 | 0.00  |
    | 8888888888   | 1      | brand1   | type4 | 9.00  |
    | etc. (10 products)                               |
    + ------------ + ------ + -------- + ----- + ----- +

谁帮帮我？：）

Answer 1

您可以使用having：

select i.EAN, p.ProductStatus,
       max(case when (info_type = 'brand' AND info_value='brand1') then info_value end) as brand,
       max(case info_type when 'type' then info_value end) as [type],
       max(case info_type when 'price' then info_value end) + 0 as price
from #Info i inner join
     #Products p
     on p.ean = i.ean
where p.Status=1
group by i.EAN, p.ProductStatus
having price < 10
order by P.Product_id DESC
LIMIT 10;

+ 0是因为info_value似乎存储为字符串。但是，您希望Price为数字，因此将其转换为数字。

Mysql查询 - 如何包含“过滤器”

1 个答案: